Colonoscopy?

[Jimbothejetset]

Hello
I'm wondering if any of you can help with the below (sorry quite long) and if you think a colonoscopy is necessary.

A blood test showed I was low in iron, folate and ferritin back in February. I have since been taking iron and folic acid. Haemoglobin is back to normal now and ferritin has slowly climbed to 20 (from 3). Folate also back to normal.
I do not have heavy periods so was referred to gasterentologist. He thinks issues caused by losing blood when having baby (2 years ago) and a history of giving blood. I also mentioned I'm about 5kg lighter than I used to be although I eat a lot and I lose weight easily now whereas previously I had to be fairly careful. I'm now underweight although weight is stable.
Gastroscopy to check for coeliacs showed no issues. Consultant thinks to take prescription milkshakes to put on weight and then in a couple of months to look into other tests if I've not managed to put on weight.
GP thinks colonoscopy should take place and so has referred me again. I have not had any change in bm so I am unsure if I need this? I have had a dull ache under my left ribs on and off for past couple of months but other than that feel ok.
Please can anyone advise? The gasterentologist obviously thinks I am burning off more calories than I am consuming (which I don't think is the case) and my GP wants to investigate any more serious causes of the anaemia and weightloss . I don't want to feel like I'm wasting people's time!
Thanks

[Badders123]

I would suggest and abdominal ultrasound would make more sense tbh

[Jimbothejetset]

Thank you will enquire about that at next appointment

[Beaverlac]

Had a similar situation a few years back, and the GP wanted to check for sources of blood loss. Had an endoscopy at the same time. I expected stomach ulcers, which a previous endoscopy revealed, to account for pain, but there was only mild gastritis. The colonoscopy found nothing, but good to know there was nothing to find. I'd opt for having it if offered.

[Jimbothejetset]

Thank you for replying

[pinkladyapple]

I would go with your gp. Not sure why you wouldn't to be honest.

[Jimbothejetset]

I'm inclined to agree with my GP, to be honest. However it is the fact the the gasterentologist didn't seem to think the colonoscopy was necessary that is making me unsure.